US12216099B2 - Detection method based on supercritical fluid chromatography and post-column ionic liquid charge complexation - Google Patents

Detection method based on supercritical fluid chromatography and post-column ionic liquid charge complexation Download PDF

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US12216099B2
US12216099B2 US17/666,721 US202217666721A US12216099B2 US 12216099 B2 US12216099 B2 US 12216099B2 US 202217666721 A US202217666721 A US 202217666721A US 12216099 B2 US12216099 B2 US 12216099B2
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Qiang Ma
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Chinese Academy of Inspection and Quarantine CAIQ
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Definitions

  • the present invention relates to the technical field of inspection and detection, and in particular relates to a detection method based on supercritical fluid chromatography (SFC) and post-column dicationic ionic liquid (DIL) charge complexation.
  • SFC supercritical fluid chromatography
  • DIL post-column dicationic ionic liquid
  • PFCs Perfluorinated compounds
  • PFCs are a class of organic compounds in which hydrogen atoms in hydrocarbons and their derivatives are replaced by fluorine atoms.
  • PFCs are commonly used in household decorative paper, food packaging materials, and surfactants in fire-fighting foams.
  • textile manufacturing PFCs are broadly used as finishing agents and surfactants.
  • PFCs have a strong bioaccumulation effect. After entering organisms, PFCs will be distributed in serum and liver, resulting in a variety of toxic effects on organisms, such as liver toxicity, cardiovascular toxicity, developmental toxicity, immune system toxicity, endocrine disruption, and potential carcinogenicity.
  • SUPRASs supramolecular solvents
  • the technical problem to be solved in the present invention is to provide a detection method using SFC separation, post-column DIL-based charge complexation, and electrospray ionization-mass spectrometry (ESI-MS).
  • Compressed carbon dioxide is the primary mobile phase used in SFC, showing advantageous properties of lower cost, safety benefits, and environmental friendliness characteristics compared to organic solvents. Moreover, SFC is capable of achieving rapid and efficient separation with high reproducibility and reduction in consumption of organic solvents.
  • Negative-ion ESI-MS has been commonly used for the detection of PFCs. However, negative-ion ESI-MS is less sensitive compared to positive-ion ESI-MS.
  • Room temperature ionic liquids are salts with melting points below 100° C. and have been regarded as promising green solvents because of the properties such as thermal stability, nonflammability, low viscosity, good electric conductivity, and tunable immiscibility.
  • DILs are a novel class of ionic liquids consisting of a dication paired with two anions and can be used as post-column ion-pairing reagents for SFC.
  • the invention relates to a detection method based on SFC and post-column DIL charge complexation, which includes the following steps:
  • the SUPRAS was prepared by mixing heptanol, tetrahydrofuran, and water;
  • the preparation of SUPRAS included the following steps: Aliquots of 3 mL of heptanol, 4 mL of tetrahydrofuran, and 33 mL of water were transferred into a 50-mL glass centrifuge tube, mixed for 3 min on a vortexer, and centrifuged at 3000 r/min for 10 min. The resulting SUPRAS supernatant was collected with a glass syringe and stored at 4° C.
  • the sample pretreatment process included the following steps: Aliquots of 0.50 g of samples were weighed in a 10-mL centrifuge tube, into which 4 mL of the obtained SUPRAS was then added. After vortexing for 3 min, the extract was centrifuged at 3000 r/min for 10 min. Aliquots of 100 ⁇ L supernatant portion was collected and diluted 1:1 (v/v) with methanol. The mixture was vortexed and filtered through a 0.22- ⁇ m microporous membrane prior to SFC-MS analysis.
  • the SFC-MS method used the following chromatographic conditions:
  • a Torus DIOL chromatographic column (2.1 mm ⁇ 100 mm, 1.7 ⁇ m) was used.
  • the binary mobile phase was composed of pressurized carbon dioxide (A) paired with 0.1% ammonia in methanol (B).
  • the initial conditions were 5% B, and the linear elution gradient was then programmed from 5% B to 20% B within 8.9 min, and held for 0.1 min. At 9.5 min, the gradient was linearly returned to 5% B and maintained for 0.5 min to complete the whole run.
  • the column temperature was set to 40° C.
  • the flow rate was 0.3 mL/min.
  • the automatic back pressure regulator (ABPR) pressure was set to 2000 psi.
  • a sampling volume of 2 ⁇ L was injected.
  • the flow rate of make-up solvent was 0.2 mL/min.
  • a DIL (1,1′-dioctyl-4,4′-bipyridinium dibromide) was dissolved in the make-up solvent of SFC and introduced post-column but before the ESI source.
  • the make-up solvent was a mixture of methanol and water at a ratio of 1:1 (v/v).
  • the mass spectrometric parameters were set as follows:
  • the ESI source under positive ion mode enabled ionization of the analytes with a capillary voltage of 2.30 kV and a nitrogen desolvation gas of 150 L/hr at 350° C.
  • a source temperature of 150° C., collision gas of 0.25 L/hr, and nitrogen cone gas at a flow rate of 150 L/hr were set for the experiments.
  • the PFCs analytes included perfluorododecanoic acid (PFDoDA), perfluorododecanoic acid (PFUnDA), perluorodecanoic acid (PFDA), perfluorononanoic acid (PFNA), perfluorooctanoate (PFOA), perfluoroheptanoic acid (PFHpA), perfluorohexanoic acid (PFHA), perfluoropentanoic acid (PFPA), perfluorooctane sulfonate (PFOS), and perfluorobutane sulfonate (PFBS).
  • PFDoDA perfluorododecanoic acid
  • PFUnDA perfluorododecanoic acid
  • PFNA perfluorononanoic acid
  • PFOA perfluorooctanoate
  • PFHpA perfluoroheptanoic acid
  • PFHA perfluorohexanoic acid
  • the invention established an analytical method incorporating SFC separation, post-column DIL-based charge complexation and ESI-MS.
  • the DIL reagent formed positively charged complexes with anionic target analytes during the ESI process, facilitating MS detection of the analytes in the positive ion mode with enhanced detection sensitivity.
  • the factors affecting the extraction yield of SUPRAS were optimized by single factor experiment and response surface methodology.
  • FIG. 1 A is a schematic diagram of the effect of alkyl alcohol type on extraction yield.
  • FIG. 1 B is a schematic diagram of the effect of amount of heptanol on extraction yield.
  • FIG. 1 C is a schematic diagram of the effect of amount of tetrahydrofuran on extraction yield.
  • FIG. 1 D is a schematic diagram of the effect of vortex time on extraction yield.
  • FIG. 2 A is a response surface plot of amounts of tetrahydrofuran and heptanol.
  • FIG. 2 B is a response surface plot of vortex time and amount of heptanol.
  • FIG. 2 C is a response surface plot of amounts of heptanol and SUPRAS.
  • FIG. 2 D is a response surface plot of vortex time and amount of tetrahydrofuran.
  • FIG. 2 E is a response surface plot of amounts of tetrahydrofuran and SUPRAS.
  • FIG. 2 F is a response surface plot of vortex time and amount of SUPRAS.
  • FIG. 3 A is a multiple reaction monitoring (MRM) chromatogram of PFDoDA in the positive ion mode.
  • FIG. 3 B is a MRM chromatogram of PFUnDA in the positive ion mode.
  • FIG. 3 C is a MRM chromatogram of PFOS in the positive ion mode.
  • FIG. 3 D is a MRM chromatogram of PFBS in the positive ion mode.
  • FIG. 3 E is a MRM chromatogram of PFDA in the positive ion mode.
  • FIG. 3 F is a MRM chromatogram of PFNA in the positive ion mode.
  • FIG. 3 G is a MRM chromatogram of PFOA in the positive ion mode.
  • FIG. 3 H is a MRM chromatogram of PFHpA in the positive ion mode.
  • FIG. 3 I is a MRM chromatogram of PFHA in the positive ion mode.
  • FIG. 3 J is a MRM chromatogram of PFPA in the positive ion mode.
  • FIG. 4 A is a total ion current chromatogram for the analysis of the 10 PFCs in the negative ion mode without post-column addition of DIL.
  • FIG. 4 B is a total ion current chromatogram for the analysis of the 10 PFCs in the positive ion mode with post-column addition of DIL.
  • FIG. 4 C is a multiple reaction monitoring chromatogram of PFBS in the negative ion mode without post-column addition of DIL.
  • FIG. 4 D is a multiple reaction monitoring chromatogram of PFOS in the negative ion mode without post-column addition of DIL.
  • FIG. 4 E is a multiple reaction monitoring chromatogram of PFBS in the positive ion mode with post-column addition of DIL.
  • FIG. 4 F is a multiple reaction monitoring chromatogram of PFOS in the positive ion mode with post-column addition of DIL.
  • PFDoDA perfluorododecanoic acid
  • PFUnDA perfluoroundecanoic acid
  • PFDA perluorodecanoic acid
  • PFNA perfluorononanoic acid
  • PFOA perfluorooctanoate
  • PFHA perfluoroheptanoic acid
  • PFHA perfluorohexanoic acid
  • PFPA perfluoroopentanoic acid
  • PFOS perfluorooctane sulfonate
  • PFBS perfluorobutane sulfonate
  • 1,1′-Dimethyl-4,4-bipyridinium dichloride, 4-aza-1-azoniabicyclo[2.2.2]octane, 1,1′-[1,4-phenylenebis(methylene)]bis(4,4′-bipyridinium) dibromide, 1,1′-diheptyl-4,4′-bipyridinium dibromide, and 1,1′-dioctyl-4,4′-bipyridinium dibromide were obtained from Sigma-Aldrich (St. Louis, MO, USA). Ultrapure water was produced using a Millipore Milli-Q Integral 5 water purification system (Bedford, MA, USA).
  • Pentanol, hexanol, octanol, decanol, undecanol, and dodecanol were obtained from J&K Scientific Ltd. (Beijing, China). Heptanol and nonanol were purchased from Tokyo Chemical Industry Co., Ltd. (Tokyo, Japan).
  • a Torus DIOL chromatographic column (2.1 mm ⁇ 100 mm, 1.7 ⁇ m) was used.
  • the binary mobile phase was composed of pressurized carbon dioxide (A) paired with 0.1% ammonia in methanol (B).
  • the initial conditions were 5% B, and the linear elution gradient was then programmed from 5% B to 20% B within 8.9 min, and held for 0.1 min. At 9.5 min, the gradient was linearly returned to 5% B and maintained for 0.5 min to complete the whole run.
  • the column temperature was set to 40° C.
  • the flow rate was 0.3 mL/min.
  • the ABPR pressure was set to 2000 psi.
  • a sampling volume of 2 ⁇ L was injected.
  • the flow rate of make-up solvent was 0.2 mL/min.
  • a DIL (1,1′-dioctyl-4,4′-bipyridinium dibromide) was dissolved in the make-up solvent of SFC and introduced post-column but before the ESI source.
  • the make-up solvent was a mixture of methanol and water at a ratio of 1:1 (v/v).
  • the mass spectrometric parameters were set as follows:
  • the ESI source under positive ion mode enabled ionization of the analytes with a capillary voltage of 2.30 kV and a nitrogen desolvation gas of 150 L/hr at 350° C.
  • a source temperature of 150° C., collision gas of 0.25 L/hr, and nitrogen cone gas at a flow rate of 150 L/hr were set for the experiments.
  • FIG. 4 A is a total ion current chromatogram for the analysis of the 10 PFCs in the negative ion mode without post-column addition of DIL.
  • FIG. 4 B is a total ion current chromatogram for the analysis of the 10 PFCs in the positive ion mode with post-column addition of DIL.
  • FIG. 4 C is a multiple reaction monitoring chromatogram of PFBS in the negative ion mode without post-column addition of DIL.
  • FIG. 4 D is a multiple reaction monitoring chromatogram of PFOS in the negative ion mode without post-column addition of DIL.
  • FIG. 4 E is a multiple reaction monitoring chromatogram of PFBS in the positive ion mode with post-column addition of DIL.
  • FIG. 4 B is a total ion current chromatogram for the analysis of the 10 PFCs in the positive ion mode with post-column addition of DIL.
  • FIG. 4 C is a multiple reaction monitoring
  • FIG. 4 F is a multiple reaction monitoring chromatogram of PFOS in the positive ion mode with post-column addition of DIL.
  • the multiple reaction monitoring (MRM) chromatograms shown in FIG. 4 C , FIG. 4 D , FIG. 4 E and FIG. 4 F were obtained for the detection of PFBS and PFOS at 10 ng/mL using 2.5 ⁇ M dissolved in methanol/water mixture solution (1:1, v/v) at a flow rate of 1.5 mL/min.
  • Significant enhancement in S/N and signal intensity was achieved in the positive ionization mode compared to the negative ionization mode.
  • the peak shape of the analytes at low concentrations in the negative ion mode could easily be distorted due to the unstable ionization.
  • the peak shape in the positive ion mode was much better.
  • the ESI source under positive ion mode enabled ionization of the analytes with a capillary voltage of 2.30 kV and a nitrogen desolvation gas of 150 L/hr at 350° C.
  • a source temperature of 150° C., collision gas of 0.25 L/hr, and nitrogen cone gas at a flow rate of 150 L/hr were set for the experiments.
  • FIG. 3 A is a multiple reaction monitoring chromatogram of PFDoDA in the positive ion mode.
  • FIG. 3 B is a multiple reaction monitoring chromatogram of PFUnDA in the positive ion mode.
  • FIG. 3 C is a multiple reaction monitoring chromatogram of PFOS in the positive ion mode.
  • FIG. 3 D is a multiple reaction monitoring chromatogram of PFBS in the positive ion mode.
  • FIG. 3 E is a multiple reaction monitoring chromatogram of PFDA in the positive ion mode.
  • FIG. 3 F is a multiple reaction monitoring chromatogram of PFNA in the positive ion mode.
  • FIG. 3 G is a multiple reaction monitoring chromatogram of PFOA in the positive ion mode.
  • FIG. 3 A is a multiple reaction monitoring chromatogram of PFDoDA in the positive ion mode.
  • FIG. 3 B is a multiple reaction monitoring chromatogram of PFUnDA in the positive ion mode.
  • FIG. 3 C is
  • FIG. 3 H is a multiple reaction monitoring chromatogram of PFHpA in the positive ion mode.
  • FIG. 3 I is a multiple reaction monitoring chromatogram of PFHA in the positive ion mode.
  • FIG. 3 J is a multiple reaction monitoring chromatogram of PFPA in the positive ion mode.
  • alkyl alcohols with different carbon numbers were mixed with tetrahydrofuran and water to form SUPRAS for the extraction of PFCs in textiles.
  • FIG. 1 A the extraction recovery of PFCs in heptanol/tetrahydrofuran/water system was 91-106%, and the recovery was relatively stable.
  • heptanol was selected as the best suited among the alkyl alcohols investigated.
  • the amount of heptanol (1-6 mL) was also evaluated.
  • FIG. 1 D is a schematic diagram of the effect of vortex time on extraction yield.
  • FIG. 2 A is a response surface plot of amounts of tetrahydrofuran and heptanol.
  • FIG. 2 B is a response surface plot of vortex time and amount of heptanol.
  • FIG. 2 C is a response surface plot of amounts of heptanol and SUPRAS.
  • FIG. 2 D is a response surface plot of vortex time and amount of tetrahydrofuran.
  • FIG. 2 E is a response surface plot of amounts of tetrahydrofuran and SUPRAS.
  • FIG. 2 F is a response surface plot of vortex time and amount of SUPRAS.
  • the optimal extraction conditions obtained by response surface methodology were as follows: 4 mL of heptanol, 4 mL of tetrahydrofuran, 3 mL of SUPRAS, and 1 min of vortex time.
  • the process was repeated three times to extract PFCs under optimal condition.
  • the experimental results under this condition were 106.337%, 108.599%, and 107.840%, with an average value of 107.592%.
  • the relative error between experimental value and predicted value (108.105%) was 0.474%.
  • the DIL acted as the derivatization reagent for the post-column adducts.
  • the chromatographic effluent was combined post-column with a make-up solvent containing a DIL reagent, leading to the detection of positively charged complexes in the positive ion mode.
  • 1,1′-dioctyl-4,4′-bipyridinium dibromide was identified as the most effective, and the total signal intensity and detection sensitivity of the 10 PFCs were the highest. Therefore, 1,1′-dioctyl-4,4′-bipyridinium dibromide was used in the make-up solvent. The dissolving solvent, concentration, and flow rate were optimized.
  • the concentration of 1,1′-dioctyl-4,4′-bipyridinium dibromide (20, 15, 10, 5, 4, 3, 2, 1, 0.8, and 0.6 ⁇ M) was optimized, among which the most intense signal intensity and S/N value were obtained at a concentration of 2.5 ⁇ M.
  • the flow rate of the make-up solvent was then optimized in the range of 1-2.5 mL/min. It was observed that the maximum signal intensity and best peak shape were obtained at a flow rate of 1.5 mL/min.

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Abstract

The invention discloses a detection method based on supercritical fluid chromatography (SFC) and post-column dicationic ionic liquid (DIL) charge complexation, which includes the following steps: (1) The supramolecular solvent (SUPRAS) was prepared by mixing heptanol, tetrahydrofuran, and water; (2) Sample pretreatment: the SUPRAS was used to extract the sample for subsequent analysis; (3) Analysis of perfluorinated compounds (PFCs) using SFC separation, post-column DIL-based charge complexation, and electrospray ionization-mass spectrometry (ESI-MS). The invention established a novel analytical method for the detection of PFCs in textiles incorporating post-chromatographic DIL-based charge complexation and SFC coupled with ESI-MS. The DIL reagent formed positively charged complexes with anionic analytes during the ESI process, facilitating MS detection in the positive ion mode with enhanced detection sensitivity.

Description

CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation application of International Patent Application No. PCT/CN2021/070260, filed on Jan. 5, 2021, which itself claims priority to and benefit of Chinese Patent Application No. 202010085113.1 filed on Feb. 10, 2020 in the State Intellectual Property Office of P.R. China. The disclosure of each of the above applications is incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
The present invention relates to the technical field of inspection and detection, and in particular relates to a detection method based on supercritical fluid chromatography (SFC) and post-column dicationic ionic liquid (DIL) charge complexation.
BACKGROUND OF THE INVENTION
Perfluorinated compounds (PFCs) are a class of organic compounds in which hydrogen atoms in hydrocarbons and their derivatives are replaced by fluorine atoms. PFCs are commonly used in household decorative paper, food packaging materials, and surfactants in fire-fighting foams. In textile manufacturing, PFCs are broadly used as finishing agents and surfactants. However, PFCs have a strong bioaccumulation effect. After entering organisms, PFCs will be distributed in serum and liver, resulting in a variety of toxic effects on organisms, such as liver toxicity, cardiovascular toxicity, developmental toxicity, immune system toxicity, endocrine disruption, and potential carcinogenicity.
Currently, solid-phase microextraction, ultrasonic extraction, and Soxhlet extraction have been reported for textile sample pretreatment. Nevertheless, these methods are not only time-consuming and use large amounts of organic solvents, but also have a negative impact on the environment and laboratory personnel. As nanostructured liquids, supramolecular solvents (SUPRASs) can improve the extraction efficiency of analytes, reduce extraction time, and consume less solvent. SUPRASs have progressively become a suitable green alternative to conventional organic solvents for sample pretreatment.
SUMMARY OF THE INVENTION
The technical problem to be solved in the present invention is to provide a detection method using SFC separation, post-column DIL-based charge complexation, and electrospray ionization-mass spectrometry (ESI-MS).
Compressed carbon dioxide is the primary mobile phase used in SFC, showing advantageous properties of lower cost, safety benefits, and environmental friendliness characteristics compared to organic solvents. Moreover, SFC is capable of achieving rapid and efficient separation with high reproducibility and reduction in consumption of organic solvents.
Negative-ion ESI-MS has been commonly used for the detection of PFCs. However, negative-ion ESI-MS is less sensitive compared to positive-ion ESI-MS. Room temperature ionic liquids are salts with melting points below 100° C. and have been regarded as promising green solvents because of the properties such as thermal stability, nonflammability, low viscosity, good electric conductivity, and tunable immiscibility. DILs are a novel class of ionic liquids consisting of a dication paired with two anions and can be used as post-column ion-pairing reagents for SFC.
The invention relates to a detection method based on SFC and post-column DIL charge complexation, which includes the following steps:
(1) The SUPRAS was prepared by mixing heptanol, tetrahydrofuran, and water;
(2) Sample pretreatment: the SUPRAS was used to extract the sample for subsequent analysis;
(3) Analysis of PFCs using supercritical fluid chromatography-mass spectrometry (SFC-MS).
According to the detection method based on SFC and post-column DIL charge complexation, the preparation of SUPRAS included the following steps: Aliquots of 3 mL of heptanol, 4 mL of tetrahydrofuran, and 33 mL of water were transferred into a 50-mL glass centrifuge tube, mixed for 3 min on a vortexer, and centrifuged at 3000 r/min for 10 min. The resulting SUPRAS supernatant was collected with a glass syringe and stored at 4° C.
According to the detection method based on SFC and post-column DIL charge complexation, the sample pretreatment process included the following steps: Aliquots of 0.50 g of samples were weighed in a 10-mL centrifuge tube, into which 4 mL of the obtained SUPRAS was then added. After vortexing for 3 min, the extract was centrifuged at 3000 r/min for 10 min. Aliquots of 100 μL supernatant portion was collected and diluted 1:1 (v/v) with methanol. The mixture was vortexed and filtered through a 0.22-μm microporous membrane prior to SFC-MS analysis.
According to the detection method based on SFC and post-column DIL charge complexation, the SFC-MS method used the following chromatographic conditions:
A Torus DIOL chromatographic column (2.1 mm×100 mm, 1.7 μm) was used. The binary mobile phase was composed of pressurized carbon dioxide (A) paired with 0.1% ammonia in methanol (B). The initial conditions were 5% B, and the linear elution gradient was then programmed from 5% B to 20% B within 8.9 min, and held for 0.1 min. At 9.5 min, the gradient was linearly returned to 5% B and maintained for 0.5 min to complete the whole run. The column temperature was set to 40° C. The flow rate was 0.3 mL/min. The automatic back pressure regulator (ABPR) pressure was set to 2000 psi. A sampling volume of 2 μL was injected. The flow rate of make-up solvent was 0.2 mL/min.
According to the detection method based on SFC and post-column DIL charge complexation, after SFC separation, a DIL (1,1′-dioctyl-4,4′-bipyridinium dibromide) was dissolved in the make-up solvent of SFC and introduced post-column but before the ESI source. The make-up solvent was a mixture of methanol and water at a ratio of 1:1 (v/v). The mass spectrometric parameters were set as follows:
The ESI source under positive ion mode enabled ionization of the analytes with a capillary voltage of 2.30 kV and a nitrogen desolvation gas of 150 L/hr at 350° C. A source temperature of 150° C., collision gas of 0.25 L/hr, and nitrogen cone gas at a flow rate of 150 L/hr were set for the experiments.
According to the detection method based on SFC and post-column DIL charge complexation, the PFCs analytes included perfluorododecanoic acid (PFDoDA), perfluorododecanoic acid (PFUnDA), perluorodecanoic acid (PFDA), perfluorononanoic acid (PFNA), perfluorooctanoate (PFOA), perfluoroheptanoic acid (PFHpA), perfluorohexanoic acid (PFHA), perfluoropentanoic acid (PFPA), perfluorooctane sulfonate (PFOS), and perfluorobutane sulfonate (PFBS).
TABLE 1
Chemical information for the 10 PFCs analytes
PFCs Molecular weight
PFDoDA 613.9604
PFUnDA 563.9647
PFDA 513.9679
PFNA 463.9711
PFOA 413.9743
PFHpA 363.9774
PFHA 313.9806
PFPA 263.9838
PFOS 499.9380
PFBS 299.9508
The differences between the invention and current techniques are as follows:
The invention established an analytical method incorporating SFC separation, post-column DIL-based charge complexation and ESI-MS. The DIL reagent formed positively charged complexes with anionic target analytes during the ESI process, facilitating MS detection of the analytes in the positive ion mode with enhanced detection sensitivity. Moreover, the factors affecting the extraction yield of SUPRAS were optimized by single factor experiment and response surface methodology.
The invention incorporating SFC separation, post-column DIL-based charge complexation and ESI-MS is further explained in combination with the following attached figures.
BRIEF DESCRIPTION OF THE DRAWINGS
Additional objectives, functions, and advantages of the present invention will be set forth in the description of embodiments which follow, with reference to the accompanying drawings in which:
FIG. 1A is a schematic diagram of the effect of alkyl alcohol type on extraction yield.
FIG. 1B is a schematic diagram of the effect of amount of heptanol on extraction yield.
FIG. 1C is a schematic diagram of the effect of amount of tetrahydrofuran on extraction yield.
FIG. 1D is a schematic diagram of the effect of vortex time on extraction yield.
FIG. 2A is a response surface plot of amounts of tetrahydrofuran and heptanol.
FIG. 2B is a response surface plot of vortex time and amount of heptanol.
FIG. 2C is a response surface plot of amounts of heptanol and SUPRAS.
FIG. 2D is a response surface plot of vortex time and amount of tetrahydrofuran.
FIG. 2E is a response surface plot of amounts of tetrahydrofuran and SUPRAS.
FIG. 2F is a response surface plot of vortex time and amount of SUPRAS.
FIG. 3A is a multiple reaction monitoring (MRM) chromatogram of PFDoDA in the positive ion mode.
FIG. 3B is a MRM chromatogram of PFUnDA in the positive ion mode.
FIG. 3C is a MRM chromatogram of PFOS in the positive ion mode.
FIG. 3D is a MRM chromatogram of PFBS in the positive ion mode.
FIG. 3E is a MRM chromatogram of PFDA in the positive ion mode.
FIG. 3F is a MRM chromatogram of PFNA in the positive ion mode.
FIG. 3G is a MRM chromatogram of PFOA in the positive ion mode.
FIG. 3H is a MRM chromatogram of PFHpA in the positive ion mode.
FIG. 3I is a MRM chromatogram of PFHA in the positive ion mode.
FIG. 3J is a MRM chromatogram of PFPA in the positive ion mode.
FIG. 4A is a total ion current chromatogram for the analysis of the 10 PFCs in the negative ion mode without post-column addition of DIL.
FIG. 4B is a total ion current chromatogram for the analysis of the 10 PFCs in the positive ion mode with post-column addition of DIL.
FIG. 4C is a multiple reaction monitoring chromatogram of PFBS in the negative ion mode without post-column addition of DIL.
FIG. 4D is a multiple reaction monitoring chromatogram of PFOS in the negative ion mode without post-column addition of DIL.
FIG. 4E is a multiple reaction monitoring chromatogram of PFBS in the positive ion mode with post-column addition of DIL.
FIG. 4F is a multiple reaction monitoring chromatogram of PFOS in the positive ion mode with post-column addition of DIL.
 DETAILED DESCRIPTION OF THE INVENTION
1. Materials and Apparatus
1.1. Materials
Reference standards of perfluorododecanoic acid (PFDoDA), perfluoroundecanoic acid (PFUnDA), perluorodecanoic acid (PFDA), perfluorononanoic acid (PFNA), perfluorooctanoate (PFOA), perfluoroheptanoic acid (PFHpA), perfluorohexanoic acid (PFHA), perfluoropentanoic acid (PFPA), perfluorooctane sulfonate (PFOS), and perfluorobutane sulfonate (PFBS) were purchased from Sigma-Aldrich (St. Louis, MO, USA). 1,1′-Dimethyl-4,4-bipyridinium dichloride, 4-aza-1-azoniabicyclo[2.2.2]octane, 1,1′-[1,4-phenylenebis(methylene)]bis(4,4′-bipyridinium) dibromide, 1,1′-diheptyl-4,4′-bipyridinium dibromide, and 1,1′-dioctyl-4,4′-bipyridinium dibromide were obtained from Sigma-Aldrich (St. Louis, MO, USA). Ultrapure water was produced using a Millipore Milli-Q Integral 5 water purification system (Bedford, MA, USA). Pentanol, hexanol, octanol, decanol, undecanol, and dodecanol were obtained from J&K Scientific Ltd. (Beijing, China). Heptanol and nonanol were purchased from Tokyo Chemical Industry Co., Ltd. (Tokyo, Japan).
1.2. Apparatus
ACQUITY UPC2 system and Xevo TQ-S triple quadrupole mass spectrometer fitted with an ESI source and MassLynx version 4.1 software (Waters, Milford, MA, USA); AB204-S electronic balance (Mettler Toledo, Columbus, OH, USA); Hitachi CR 21N centrifuge (Tokyo, Japan); IKA MS3 vortexer (Staufen, Germany).
2. Detection Method
2.1. Preparation of SUPRAS
Aliquots of 3 mL of heptanol, 4 mL of tetrahydrofuran, and 33 mL of water were transferred into a 50-mL centrifuge tube, mixed for 3 min on a vortexer, and centrifuged at 3000 r/min for 10 min. The resulting SUPRAS supernatant was collected and stored at 4° C.
2.2. Sample Pretreatment
Aliquots of 0.50 g of samples were weighed in a 10-mL centrifuge tube, into which 4 mL of the obtained SUPRAS was then added. After vortexing for 3 min, the extract was centrifuged at 3000 r/min for 10 min. Aliquots of 100 μL supernatant portion was collected and diluted 1:1 (v/v) with methanol. The mixture was vortexed and filtered through a 0.22-μm microporous membrane prior to SFC-MS analysis.
2.3. SFC Conditions
A Torus DIOL chromatographic column (2.1 mm×100 mm, 1.7 μm) was used. The binary mobile phase was composed of pressurized carbon dioxide (A) paired with 0.1% ammonia in methanol (B). The initial conditions were 5% B, and the linear elution gradient was then programmed from 5% B to 20% B within 8.9 min, and held for 0.1 min. At 9.5 min, the gradient was linearly returned to 5% B and maintained for 0.5 min to complete the whole run. The column temperature was set to 40° C. The flow rate was 0.3 mL/min. The ABPR pressure was set to 2000 psi. A sampling volume of 2 μL was injected. The flow rate of make-up solvent was 0.2 mL/min.
2.4. Mass Spectrometric Conditions
After SFC separation, a DIL (1,1′-dioctyl-4,4′-bipyridinium dibromide) was dissolved in the make-up solvent of SFC and introduced post-column but before the ESI source. The make-up solvent was a mixture of methanol and water at a ratio of 1:1 (v/v). The mass spectrometric parameters were set as follows:
The ESI source under positive ion mode enabled ionization of the analytes with a capillary voltage of 2.30 kV and a nitrogen desolvation gas of 150 L/hr at 350° C. A source temperature of 150° C., collision gas of 0.25 L/hr, and nitrogen cone gas at a flow rate of 150 L/hr were set for the experiments.
FIG. 4A is a total ion current chromatogram for the analysis of the 10 PFCs in the negative ion mode without post-column addition of DIL. FIG. 4B is a total ion current chromatogram for the analysis of the 10 PFCs in the positive ion mode with post-column addition of DIL. FIG. 4C is a multiple reaction monitoring chromatogram of PFBS in the negative ion mode without post-column addition of DIL. FIG. 4D is a multiple reaction monitoring chromatogram of PFOS in the negative ion mode without post-column addition of DIL. FIG. 4E is a multiple reaction monitoring chromatogram of PFBS in the positive ion mode with post-column addition of DIL. FIG. 4F is a multiple reaction monitoring chromatogram of PFOS in the positive ion mode with post-column addition of DIL. The multiple reaction monitoring (MRM) chromatograms shown in FIG. 4C, FIG. 4D, FIG. 4E and FIG. 4F were obtained for the detection of PFBS and PFOS at 10 ng/mL using 2.5 μM dissolved in methanol/water mixture solution (1:1, v/v) at a flow rate of 1.5 mL/min. Significant enhancement in S/N and signal intensity was achieved in the positive ionization mode compared to the negative ionization mode. Moreover, the peak shape of the analytes at low concentrations in the negative ion mode could easily be distorted due to the unstable ionization. However, the peak shape in the positive ion mode was much better.
2.5. Comparative MS Test in the Negative Ion Mode
The ESI source under positive ion mode enabled ionization of the analytes with a capillary voltage of 2.30 kV and a nitrogen desolvation gas of 150 L/hr at 350° C. A source temperature of 150° C., collision gas of 0.25 L/hr, and nitrogen cone gas at a flow rate of 150 L/hr were set for the experiments.
The precursor and product ions, cone voltage, and collision energy for the analysis of the 10 PFCs are shown in Table 2.
TABLE 2
The precursor ion, product ion, cone voltage and
collision energy for the analysis of the 10 PFCs.
Precursor Product Cone Collision
No. PFCs ion (m/z) ion (m/z) voltage (V) energy (V)
1 PFDoDA 613.1 569.0 10 10
2 PFUnDA 563.1 519.0 2 10
3 PFDA 513.0 469.0 22 10
4 PFNA 463.1 419.1 14 10
5 PFOA 413.0 369.0 21 10
6 PFHpA 363.1 319.0 10 10
7 PFHA 313.0 269.0 10 8
8 PFPA 263.1 219.1 10 8
9 PFOS 499.0 80.0 26 36
10 PFBS 299.0 80.0 36 30
FIG. 3A is a multiple reaction monitoring chromatogram of PFDoDA in the positive ion mode. FIG. 3B is a multiple reaction monitoring chromatogram of PFUnDA in the positive ion mode. FIG. 3C is a multiple reaction monitoring chromatogram of PFOS in the positive ion mode. FIG. 3D is a multiple reaction monitoring chromatogram of PFBS in the positive ion mode. FIG. 3E is a multiple reaction monitoring chromatogram of PFDA in the positive ion mode. FIG. 3F is a multiple reaction monitoring chromatogram of PFNA in the positive ion mode. FIG. 3G is a multiple reaction monitoring chromatogram of PFOA in the positive ion mode. FIG. 3H is a multiple reaction monitoring chromatogram of PFHpA in the positive ion mode. FIG. 3I is a multiple reaction monitoring chromatogram of PFHA in the positive ion mode. FIG. 3J is a multiple reaction monitoring chromatogram of PFPA in the positive ion mode.
3. Results and Discussion
3.1. Optimization of SUPRAS-Based Extraction with Single Factor Test
3.1.1. Optimization of Type and Amount for Alkyl Alcohols
A variety of alkyl alcohols with different carbon numbers (each of pentanol, hexanol, heptanol, octanol, nonanol, decanol, undecanol, and dodecanol) were mixed with tetrahydrofuran and water to form SUPRAS for the extraction of PFCs in textiles. As shown in FIG. 1A, the extraction recovery of PFCs in heptanol/tetrahydrofuran/water system was 91-106%, and the recovery was relatively stable. Thus, heptanol was selected as the best suited among the alkyl alcohols investigated. The amount of heptanol (1-6 mL) was also evaluated. Maintaining fixed volumes of 40 mL of SUPRAS, the extraction yield increased with increasing amount of heptanol from 1 to 3 mL but decreased thereafter (FIG. 1B). Thus, 3 mL was selected as an optimum volume for heptanol.
3.1.2. Optimization of Amount for Tetrahydrofuran
The extraction effect was assessed using a total of 40 mL of SUPRAS containing 2, 4, 6, 8, 10, or 12 mL of tetrahydrofuran (heptanol was kept at 3 mL), among which 4 mL gave the maximum and stable extraction yield. With the increase of tetrahydrofuran, the extraction yield of most compounds first decreased and then basically became stable (FIG. 1C).
3.1.3. Optimization of Vortex Time
The extraction yield of six vortex times (1, 3, 5, 7, 9, and 11 min) were evaluated. It was found that the vortex time of 3 min reached a maximum extraction yield for the 10 PFCs. With the increase of vortex time, the extraction yield tended to be stable. Therefore, 3 min was chosen for further studies. FIG. 1D is a schematic diagram of the effect of vortex time on extraction yield.
3.1.4. Optimization of SUPRAS Volume
After the composition of SUPRAS was determined, the extraction efficiency of different volumes of SUPRAS (2, 3, 4, 5, and 6 mL) was further studied. The experimental results demonstrated that the extraction yield first increased and then gradually stabilized, with 4 mL being the optimal volume of SUPRAS.
3.2. Optimization of SUPRAS-Based Extraction by Response Surface Methodology
According to the single factor test results, a comprehensive analysis of four critical variables (amounts of heptanol, tetrahydrofuran, SUPRAS, and vortex time) was carried out to examine their influences on extraction efficiency for PFCs. The interaction between the variables was analyzed using the four-factor and three-level response surface methodology. According to multiple regression analyses of the data processing with coded levels (Table 3), analysis of variance (ANOVA) of the fitted quadratic polynomial model identified a p value less than 0.0001, indicating that the regression model was of significance. The calculated lack-of-fit value was 0.2985, exhibiting that the model could sufficiently predict relevant variation while representing the actual relationship between the four variables. FIG. 2A is a response surface plot of amounts of tetrahydrofuran and heptanol. FIG. 2B is a response surface plot of vortex time and amount of heptanol. FIG. 2C is a response surface plot of amounts of heptanol and SUPRAS. FIG. 2D is a response surface plot of vortex time and amount of tetrahydrofuran. FIG. 2E is a response surface plot of amounts of tetrahydrofuran and SUPRAS. FIG. 2F is a response surface plot of vortex time and amount of SUPRAS. The results indicated that interaction between the amounts of heptanol and tetrahydrofuran (AB), interaction between the amount of heptanol and vortex time (AC), and interaction between the amounts of heptanol and SUPRAS (AD) were significantly correlated with the extraction yield of the 10 PFCs.
TABLE 3
ANOVA results for the response surface quadratic model.
Degrees of Sum of Mean F- P-
Source freedom squares square value value
Model 14 3266.21 233.30 58.47 <0.0001 significant
A
1 238.90 238.90 59.87 <0.0001
B 1 484.57 484.57 121.44 <0.0001
C 1 224.44 224.44 56.25 <0.0001
D 1 33.77 33.77 8.46 <0.0001
AB 1 660.73 660.73 165.59 0.0114
AC 1 173.14 173.14 43.39 <0.0001
AD 1 1054.68 1054.68 264.33 <0.0001
BC 1 42.60 42.60 10.68 <0.0001
BD 1 47.97 47.97 12.02 0.0056
CD 1 55.19 55.19 13.83 0.0038
A2 1 2.41 2.41 0.60 0.0023
B2 1 46.21 46.21 11.58 0.4499
C2 1 193.48 193.48 48.49 0.0043
D2 1 38.30 38.30 9.60 <0.0001
Residual 14 55.86 3.99 0.0079
Lack of 10 45.74 4.57 1.81 0.2985 not
fit significant
Pure 4 10.12 2.53
error

3.3. Model Validation
The optimal extraction conditions obtained by response surface methodology were as follows: 4 mL of heptanol, 4 mL of tetrahydrofuran, 3 mL of SUPRAS, and 1 min of vortex time. In order to confirm the accuracy of the established model, the process was repeated three times to extract PFCs under optimal condition. The experimental results under this condition were 106.337%, 108.599%, and 107.840%, with an average value of 107.592%. The relative error between experimental value and predicted value (108.105%) was 0.474%. Thus, the extraction conditions of PFCs optimized by response surface methodology are feasible and reliable.
3.4. Optimization of DILs
3.4.1. Optimization of Type for DILs
The DIL acted as the derivatization reagent for the post-column adducts. The chromatographic effluent was combined post-column with a make-up solvent containing a DIL reagent, leading to the detection of positively charged complexes in the positive ion mode. The DILs of 1,1′-dimethyl-4,4-bipyridinium dichloride, 4-aza-1-azoniabicyclo[2.2.2]octane, 1,1′-[1,4-phenylenebis(methylene)]bis(4,4′-bipyridinium) dibromide, 1,1′-diheptyl-4,4′-bipyridinium dibromide, and 1,1′-dioctyl-4,4′-bipyridinium dibromide were investigated for their ability to pair with PFCs. Among the five DILs investigated, 1,1′-dioctyl-4,4′-bipyridinium dibromide was identified as the most effective, and the total signal intensity and detection sensitivity of the 10 PFCs were the highest. Therefore, 1,1′-dioctyl-4,4′-bipyridinium dibromide was used in the make-up solvent. The dissolving solvent, concentration, and flow rate were optimized.
3.4.1. Optimization of Solvent Type and Ratio for DILs
Two make-up solvents (acetonitrile and methanol) for dissolving the DIL were evaluated. However, it was found that the baseline was too high. The solvent was then changed to a mixture of methanol/acetonitrile and water with the ratios of 1:1, 2:3, 4:1, 3:2, and 1:4. Based on the comparison in terms of response intensity and S/N value, the best results were achieved using a mixture of methanol and water at a ratio of 1:1 (v/v).
3.4.2. Optimization of DIL Concentration
The concentration of 1,1′-dioctyl-4,4′-bipyridinium dibromide (20, 15, 10, 5, 4, 3, 2, 1, 0.8, and 0.6 μM) was optimized, among which the most intense signal intensity and S/N value were obtained at a concentration of 2.5 μM.
3.4.3. Optimization of DIL Flow Rate
Maintaining a fixed concentration of 2.5 μM for 1,1′-dioctyl-4,4′-bipyridinium dibromide and methanol-water 1:1 (v/v) as the make-up solvent, the flow rate of the make-up solvent was then optimized in the range of 1-2.5 mL/min. It was observed that the maximum signal intensity and best peak shape were obtained at a flow rate of 1.5 mL/min.
3.5. Analysis of Real Samples
The proposed approach was applied to the analysis of real textile samples of different fabrics (e.g., nylon, cotton, polyester and silk). The experimental results revealed that the 10 PFCs were not detected.
The foregoing embodiments are merely illustrative of preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various variations and modifications made to the technical solutions of the present invention by those skilled in the art without departing from the spirit of the present invention are embraced in the protection scope of the present invention as defined by the appended claims.

Claims (4)

What is claimed is:
1. A detection method based on supercritical fluid chromatography (SFC) and post-column dicationic ionic liquid (DIL) charge complexation, which includes the following steps:
preparing a supramolecular solvent (SUPRAS) by mixing heptanol, tetrahydrofuran, and water;
performing sample pretreatment to extract samples by the SUPRAS and to obtain a test solution for subsequent analysis, wherein the samples are textiles;
performing an analysis of perfluorinated compounds (PFCs) in the test solution using SFC separation, post-column DIL-based charge complexation, and electrospray ionization-mass spectrometry (ESI-MS), wherein the DIL is 1,1′-dioctyl-4,4′-bipyridinium dibromide;
wherein the chromatographic conditions are as follows:
a DIOL chromatographic column (2.1 mm×100 mm, 1.7 μm) is used, a binary mobile phase is composed of pressurized carbon dioxide (A) paired with 0.1% ammonia in methanol (B), initial conditions are 5% B, and a linear elution gradient is then programmed from 5% B to 20% B within 8.9 min, and held for 0.1 min, at 9.5 min, the gradient is linearly returned to 5% B and maintained for 0.5 min to complete a whole run, a column temperature is set to 40° C., a flow rate is 0.3 mL/min, an automatic back pressure regulator (ABPR) pressure is set to 2000 psi, a sampling volume of 2 μL of the test solution is injected, and a flow rate of a make-up solvent was 0.2 mL/min, wherein the make-up solvent was a mixture of methanol and water at a ratio of 1:1 (v/v);
after the SFC separation, the DIL is dissolved in the make-up solvent of SFC and introduced post-column but before an ESI source;
wherein—the PFCs include perfluorododecanoic acid (PFDoDA), perfluoroundecanoic acid (PFUnDA), perluorodecanoic acid (PFDA), perfluorononanoic acid (PFNA), perfluorooctanoate (PFOA), perfluoroheptanoic acid (PFHpA), perfluorohexanoic acid (PFHA), perfluoropentanoic acid (PFPA), perfluorooctane sulfonate (PFOS), and perfluorobutane sulfonate (PFBS).
2. The detection method of claim 1, wherein the preparation of the SUPRAS includes the following steps:
transferring aliquots of 3 mL of heptanol, 4 mL of tetrahydrofuran, and 33 mL of water into a 50-mL glass centrifuge tube,
mixing the heptanol, the tetrahydrofuran and the water in the glass centrifuge tube for 3 min on a vortexer, and
centrifuging the glass centrifuge tube at 3000 r/min for 10 min,
wherein the resulting SUPRAS supernatant is collected with a glass syringe and stored at 4° C.
3. The detection method of claim 1, wherein the sample pretreatment process includes the following steps:
disposing aliquots of 0.50 g of the samples in a 10-mL centrifuge tube,
adding 4 mL of the obtained SUPRAS into the centrifuge tube,
vortexing the centrifuge tube for 3 min,
centrifuging the extract in the centrifuge tube at 3000 r/min for 10 min,
collecting aliquots of 100 μL supernatant portion and diluting the collected supernatant portion 1:1 (v/v) with methanol to form a mixture, and
vortexing the mixture, and filtering the vortexed mixture through a 0.22-μm microporous membrane to obtain the test solution prior to SFC-mass spectrometry analysis.
4. The detection method of claim 1,
wherein a concentration of the 1,1′-dioctyl-4,4′-bipyridinium dibromide is 2.5 μM, and a flow rate of the 1,l′-dioctyl-4,4′-bipyridinium dibromide is 1.5 mL/min;
wherein the mass spectrometric parameters are set as follows:
the ESI source under positive ion mode enabled ionization of analytes with a capillary voltage of 2.30 kV and a nitrogen desolvation gas of 150 L/hr at 350° C., a source temperature of 150° C., collision gas of 0.25 L/hr, and nitrogen cone gas at a flow rate of 150 L/hr are set for experiments.
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Families Citing this family (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111537623B (en) 2020-02-10 2021-08-13 中国检验检疫科学研究院 Determination method based on supercritical fluid chromatography and post-column addition reaction of ionic liquid
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CN116183782B (en) * 2023-04-26 2023-07-28 北京建工环境修复股份有限公司 Quantitative detection method of 8 perfluorinated compound substitutes based on alkali-assisted ionization
CN116735743B (en) * 2023-06-07 2024-03-22 重庆大学 Method for simultaneously detecting type and total amount of perfluorinated compounds in organic solid sample
CN116840388B (en) * 2023-07-05 2024-11-22 上海交通大学医学院附属新华医院 Detection method of per- and polyfluoroalkyl substances in follicular fluid
CN117491511B (en) * 2023-09-26 2024-04-16 梅里埃检测技术(宁波)有限公司 Method for detecting fluoroalkoxyphosphazene compound in food

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103197023A (en) 2013-04-20 2013-07-10 北京工业大学 Thermal desorption-gas phase-mass spectra combining method for collecting air contaminants based on ionic liquid
CN104297386A (en) 2014-11-05 2015-01-21 华文蔚 Method for adsorption and thermal desorption combined gas chromatographic-mass spectrometric measurement of benzene series in atmosphere
CN105241995A (en) 2015-11-25 2016-01-13 通标标准技术服务(上海)有限公司 Method for measuring perfluorinated compounds in textile, clad layers, coatings, liquid and powder samples
CN107121487A (en) 2017-07-05 2017-09-01 中国检验检疫科学研究院 A kind of normal pressure velocity of sound electrospray ionization device and its application
CN108318609A (en) 2018-03-24 2018-07-24 厦门市诚安毅科技有限公司 A kind of pesticide residue detection method of supermolecule solvent joint QuEChERS
CN108709947A (en) 2018-07-10 2018-10-26 中国检验检疫科学研究院 The assay method of phthalic ester plasticizer the amount of migration in food contact material
CN109507342A (en) 2019-01-21 2019-03-22 中国检验检疫科学研究院 A kind of remaining method of nitroimidazoles medicine in measurement blood sample
CN111537623A (en) 2020-02-10 2020-08-14 中国检验检疫科学研究院 Determination method based on supercritical fluid chromatography and post-column addition reaction of ionic liquid

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106226443B (en) * 2016-09-21 2019-02-05 昆明理工大学 A method for the detection of bisphenol A by supramolecular solvent extraction combined with magnetic solid phase extraction
US11506581B2 (en) * 2018-03-20 2022-11-22 Agilent Technologies, Inc. Mass spectrometry compatible salt formation for ionic liquid sample preparation

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103197023A (en) 2013-04-20 2013-07-10 北京工业大学 Thermal desorption-gas phase-mass spectra combining method for collecting air contaminants based on ionic liquid
CN104297386A (en) 2014-11-05 2015-01-21 华文蔚 Method for adsorption and thermal desorption combined gas chromatographic-mass spectrometric measurement of benzene series in atmosphere
CN105241995A (en) 2015-11-25 2016-01-13 通标标准技术服务(上海)有限公司 Method for measuring perfluorinated compounds in textile, clad layers, coatings, liquid and powder samples
CN107121487A (en) 2017-07-05 2017-09-01 中国检验检疫科学研究院 A kind of normal pressure velocity of sound electrospray ionization device and its application
CN108318609A (en) 2018-03-24 2018-07-24 厦门市诚安毅科技有限公司 A kind of pesticide residue detection method of supermolecule solvent joint QuEChERS
CN108709947A (en) 2018-07-10 2018-10-26 中国检验检疫科学研究院 The assay method of phthalic ester plasticizer the amount of migration in food contact material
CN109507342A (en) 2019-01-21 2019-03-22 中国检验检疫科学研究院 A kind of remaining method of nitroimidazoles medicine in measurement blood sample
CN111537623A (en) 2020-02-10 2020-08-14 中国检验检疫科学研究院 Determination method based on supercritical fluid chromatography and post-column addition reaction of ionic liquid

Non-Patent Citations (4)

* Cited by examiner, † Cited by third party
Title
Guoping Li et al., Post-Chromatographic Dicationic lonic Liquid-Based Charge Complexation for Highly Sensitive Analysis of Anionic Compounds by Ultra-High-Performance Supercritical Fluid Chromatography Coupled with Electrospray Ionization Mass Spectrometry, Anal. Chem., 2020, 93, 3, 1771-1778.
Lu Zhao et al., Enantioseparation of chiral perfluorooctane sulfonate(PFOS) by supercritical fluid chromatography (SFC):Effects of the chromatographic conditions and separation mechanism, Chirality, 2019, 31: 870-878.
Xiuli Lin et al., CE-ESI-MS analysis of singly charged inorganic and organic anions using a dicationic reagent as a complexing agent, Electrophoresis, 2009, 30, 3918-3925.
Yueguang Lv et al., Direct Mass Spectrometry Analysis Using In-Capillary Dicationic lonic Liquid-Based in Situ Dispersive Liquid-Liquid Microextraction and Sonic-Spray Ionization, Anal. Chem., 2019, 91, 10, 6661-6668.

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